Research On Adaptability Of Air Braking System For Heavy Haul Train

With the increasing trains weight of heavy haul train,train braking system,as one of the key parts to ensure the safe operation of train,has attracted more and more attention from all countries.The train braking system is composed of three parts : locomotive automatic brake system,vehicle braking system and train tail device.The perfect coordination among the three parts can realize the function of train braking system.If the two of three are not coordinated,the train braking system will produce misoperation,which can not achieve effective train speed control,or even accidents.In addition,the experimental research on the matching problem of train braking system is of great workload and difficulty.Therefore,it is of great practical significance to establish the model of train braking system and simulate the adaptability between subsystems of train braking system.In this paper,the combined simulation system of train air brake and longitudinal dynamics is used to establish a complete simulation model of locomotive-vehicle-exhausting device of tail brake system.Taking 20,000 t heavy haul combined train as the research object,the influence of exhaust rate difference between locomotive and the exhausting device of tail on train exhaust characteristics is simulated,and the influence of the exhausting device of tail exhaust characteristics on pressure fluctuation of tail vehicle is explored,and the influence of minor leakage of auxiliary reservoir on train braking is preliminarily explored.The simulation results show that the change of locomotive exhaust rate in the train braking system has little effect on the pressure fluctuation of train pipe,and the change of the exhausting device of tail exhaust rate has great effect on the pressure fluctuation of tail train pipe;After the exhausting device of tail stops exhaust,the closer to the exhausting device of tail,the higher the train pipe echo pressure;adjust the duration of the echo suppression program to 4.7 s,and the echo suppression program starts when the pressure reduction of the tail train pipe is 90% of the target reduction amount,the pressure difference of the tail train pipe reduction echo can meet the requirements of the standard less than 5 k Pa;When the leakage of the auxiliary reservoir is slightly larger than that of the tear hole air supply,the vehicle located between the main control locomotive and the slave control locomotive first slows down due to the slight leakage of the auxiliary reservoir;The leakage rate of the auxiliary reservoir should not exceed 0.013 k Pa/s(0.009 k Pa/s)if the train pipe pressure holding after train braking for 10 min(20 min),and the vehicle does not naturally alleviate.